The overall objective of the project is to characterize EBNA as a protein and to study a variety of its properties. The major goal at the present time is to develop a reproducible procedure for the purification of EBNA and to study its possible heterogeneity. The major approach employed to study this problem is the development of monoclonal antibodies which could be used in immunoaffinity purification and which might also provide clues to heterogeneity of EBNA.